The invention relates to sight glasses for determining the liquid level in containers for liquids and in particular to sight glasses for containers requiring primarily a decision as to the liquid level being satisfactory or in the need of additional liquid to be added. Specifically, it relates to such containers for liquid such as automobile radiators, household tanks for oil, and similar containers of a liquid requiring a check on the level of the liquid for safety reasons or the like.
In the prior art there are numerous sight gauges, several invented by the present inventor. However, the sight gauges of the prior art are of a complicated nature, require double sealing (often on both sides of the aperture), require extra washers at the seal, special spanner-type wrenches to service, slippage members, or the sight glass itself is threaded and subject to continual breakage. These and other manufacturing, installation, and maintenance problems gave rise to the present invention to solve this plurality of problems.
The present invention is designed to be installed into a tapered threaded aperture. Should the aperture be an existing straight or perpendicular threaded aperture, a Teflon tape wrapping will overcome this difficulty if it provides a problem.
The present invention has a main body into which a single threaded retainer compresses a simple unthreaded sight glass against one single simple seal. This simple four piece assembly constitutes the improved safety sight that overcomes the problems encountered in the prior art. Standard nut wrenches may be used for the installation and servicing.
It is, therefore, an object of the invention to provide a safety sight for liquid level detection in a liquid container.
It is also an object of the invention to provide a safety sight that can be used in pressure vessels or vessels having atmospheric pressure only.
It is another object of the invention to provide a safety sight that requires only one single seal.
It is still another object of the invention to provide a safety sight that is simple to manufacture, install, and maintain.
It is yet another object of the invention to provide a safety sight that is generally installed in a tapered threaded aperture in a liquid container.
It is a further object of the invention to provide a safety sight that is suitable for multiple installation to detect a range of liquid levels in a liquid container.
It is also another object of the invention to provide a safety sight that can have the sight glass element replaced without breaking the connection to the liquid container.
It is yet still another object of the invention to provide a safety sight that requires only a standard nut wrench to install and service.
Further objects and advantages of the invention will become more apparent in light of the following description of the preferred embodiments.